DEFLATE compresses:
American.Made.2017.INTERNAL.1080p.BluRay.X264-DEFLATE

Release Date : 2017-12-05
URL          : http://www.imdb.com/title/tt3532216

Duration     : 1h 54mn 58s
Video        : X264 ba24899 @ CRF 19.0000
Resolution   : 1920x1038 / 1.850:1
Frame Rate   : 23.976 fps
Audio        : DTS X / MA / Core (7.1+5.1 / 24bits)
Language     : English
Subtitles    : English (Forced), English, English (SDH), English (SDH),
English (Forced), Arabic, Chinese, Danish, Dutch, Finnish,
French, French (Forced), German, German (Forced), Hindi,
Icelandic, Italian, Italian (Forced), Norwegian, Portuguese,
Spanish, Spanish (Forced), Swedish
Size         : 18,232.038 MB (19,117,677,405 bytes)
Notes        : CRF, mod2, DTS-MA, srt+sups > 2pass, mod8, core, vobsubs

CRF+2.00 to stay below roughly ~70% of the source bitrate

14.87 Mbit/s / 23.16 Mbit/s = 64.20%

Quick maths!